'keys' must be defined for host-key-checking: false

If host-key-checking is set to false the aws driver
fails with an UnboundLocalError

Change-Id: I91ec292a48e283f9fb8d60b944da8eaf1bec393b

nodepool/driver/aws/config.py

@@ -230,6 +230,7 @@ class AwsProviderConfig(ProviderConfig):
         pool.update({
             v.Required('name'): str,
             v.Required('labels'): [pool_label],
+            'host-key-checking': bool,
             'security-group-id': str,
             'subnet-id': str,
         })

nodepool/driver/aws/handler.py

@@ -80,6 +80,7 @@ class AwsInstanceLauncher(NodeLauncher):
 
         self.node.connection_port = self.label.cloud_image.connection_port
         self.node.connection_type = self.label.cloud_image.connection_type
+        keys = []
         if self.pool.host_key_checking:
             try:
                 if (self.node.connection_type == 'ssh' or

nodepool/tests/fixtures/aws.yaml

@@ -9,6 +9,7 @@ labels:
   - name: ubuntu1404-by-filters
   - name: ubuntu1404-by-capitalized-filters
   - name: ubuntu1404-bad-config
+  - name: ubuntu1404-non-host-key-checking
 
 providers:
   - name: ec2-us-west-2
@@ -66,3 +67,13 @@ providers:
             cloud-image: ubuntu1404-bad-config
             instance-type: t3.medium
             key-name: zuul
+      - name: non-host-key-checking
+        max-servers: 1
+        subnet-id: null
+        security-group-id: null
+        host-key-checking: false
+        labels:
+          - name: ubuntu1404-non-host-key-checking
+            cloud-image: ubuntu1404
+            instance-type: t3.medium
+            key-name: zuul

nodepool/tests/unit/test_driver_aws.py

@@ -63,8 +63,12 @@ class TestDriverAws(tests.DBTestCase):
         }
         raw_config['providers'][0]['pools'][0]['subnet-id'] = subnet_id
         raw_config['providers'][0]['pools'][0]['security-group-id'] = sg_id
+        raw_config['providers'][0]['pools'][1]['subnet-id'] = subnet_id
+        raw_config['providers'][0]['pools'][1]['security-group-id'] = sg_id
 
-        def _test_run_node(label, is_valid_config=True):
+        def _test_run_node(label,
+                           is_valid_config=True,
+                           host_key_checking=True):
             with tempfile.NamedTemporaryFile() as tf:
                 tf.write(yaml.safe_dump(
                     raw_config, default_flow_style=False).encode('utf-8'))
@@ -95,11 +99,12 @@ class TestDriverAws(tests.DBTestCase):
                     self.assertEqual(node.state, zk.READY)
                     self.assertIsNotNone(node.launcher)
                     self.assertEqual(node.connection_type, 'ssh')
-                    nodescan.assert_called_with(
-                        node.interface_ip,
-                        port=22,
-                        timeout=180,
-                        gather_hostkeys=True)
+                    if host_key_checking:
+                        nodescan.assert_called_with(
+                            node.interface_ip,
+                            port=22,
+                            timeout=180,
+                            gather_hostkeys=True)
 
                     # A new request will be paused and for lack of quota
                     # until this one is deleted
@@ -136,8 +141,11 @@ class TestDriverAws(tests.DBTestCase):
             {"label": "ubuntu1404-by-capitalized-filters"},
             {"label": "ubuntu1404-bad-ami-name", "is_valid_config": False},
             {"label": "ubuntu1404-bad-config", "is_valid_config": False},
+            {"label": "ubuntu1404-non-host-key-checking",
+             "host_key_checking": False},
         ]
 
         for cloud_image in cloud_images:
             _test_run_node(cloud_image["label"],
-                           cloud_image.get("is_valid_config"))
+                           cloud_image.get("is_valid_config"),
+                           cloud_image.get("host_key_checking"))